1. Field of the Invention
Embodiments of the present invention relate to an organic light emitting display device and a driving method thereof.
2. Discussion of the Related Art
Recently, with the advancement of multimedia, the importance of flat panel display (FPD) devices is increasing. Therefore, various FPD devices such as liquid crystal display (LCD) devices, plasma display panel (PDP) devices, and organic light emitting display devices are being used practically. The organic light emitting display devices display an image by emitting light from an organic light emitting diode according to a recombination of an electron and a positive hole. The organic light emitting display devices have a fast response time and an unrestricted viewing angle because of their self-emitting light, and thus are attracting much attention as next generation FPD devices.
FIG. 1 is a circuit diagram for describing a pixel structure of a related art organic light emitting display device.
With reference to FIG. 1, each pixel P of the organic light emitting display device may include a switching transistor Tsw, a driving transistor Tdr, a capacitor Cst, and an organic light emitting diode OLED.
The switching transistor Tsw may be turned on according to a scan pulse SP supplied to a scan line SL, and may supply a data voltage Vdata, supplied through a data line DL, to the driving transistor Tdr.
The driving transistor Tdr may be turned on with the data voltage Vdata supplied from the switching transistor Tsw, and may control a data current holed which flows to the organic light emitting diode OLED with a driving voltage EVdd supplied through a driving power line.
The capacitor Cst may be connected between a gate and source of the driving transistor Tdr, may store a voltage corresponding to the data voltage Vdata supplied to the gate of the driving transistor Tdr, and may turn on the driving transistor Tdr with the stored voltage.
The organic light emitting diode OLED may be electrically connected between the source of the driving transistor Tdr and a cathode line EVss, and may emit light with the data current holed supplied from the driving transistor Tdr.
Each pixel P of the organic light emitting display device may control a level of the data current holed, which flows to the light emitting diode OLED, with a switching time of the driving transistor Tdr based on the data voltage Vdata to emit light from the light emitting diode OLED, thereby displaying an image.
However, in the organic light emitting display device of the related art, a driving characteristic of the driving transistor Tdr may change due to non-uniformity of a manufacturing process of a thin film transistor (TFT) and its sequential deterioration. For this reason, the quality of an image may not be uniform.